sodium is excreted with the use of diuretics, reduced sodium decreases lithium excretion , which can lead to toxicity
NSAIDS (ibuprofen), celexicob (Celebrex)- increases renal reabsorption of lithium- leading to toxicity
anticholinergics (antihistamine, TCAs) can induce urinary retention and polyuria

lithium administration

maintenance level 0.4-1.0 mEq/L
plasma levels greater than 1.5 can result in toxicity
effects begin in 7-14 days
must be administered in 2-3 doses daily due to a short half-life
take with food to decrease GI distress